. >> reporter: megan and her little sister maddie were christmas shopping when maddie spotted a toy sewing machine. >> they got it for me and she had the bag in her hand. >> reporter: the girls parents were randomly handed a bag by a man and woman and inside. >> we both looked in the bag and just said wow. how did they know that she wanted that toy. >> it's the sewing machine she wanted. >> reporter: the couple didn't give their names but employees spotted them hugging one another after their generous deed. joyce was working the cash register that day. she'll never forget. >> he handed me the money and says merry christmas to her. she started crying. and then i started crying. >> reporter: maddie's dad recalls another charming characteristic. >> their joy of living it to her. just never forget their laugh of joy. >> reporter: the couple spent thousands of dollars that day on merchandise. >> not wanting to be known. not wanting to be seen. they specifically made the comment there was no cameras, we're not here to get recognition. >> reporter: as for maddie, she has a message for the secret